Question: $ { \left[\begin{array}{rrr}{4} & {-2} & {-1} \\ {1} & {-2} & {2}\end{array}\right]-\left[\begin{array}{rrr}{-1} & {-1} & {-2} \\ {-1} & {3} & {2}\end{array}\right] = {?} } $
Answer: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rrr}{4}-{-1} & {-2}-{-1} & {-1}-{-2} \\ {1}-{-1} & {-2}-{3} & {2}-{2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{5} & {-1} & {1} \\ {2} & {-5} & {0}\end{array}\right]}$